Solar thermal active systems : from closed form models to simple sizing rules for collector circuits

Paper presented at ISES Solar World Congress (International Solar Energy Society), Hamburg, Germany, Sept. 1987International audienceA simple closed-form model of thermal solar active systems (Space or Water heating) is presented. It deals both with fully-mixed storage and perfectly stratified storage and enables a better understanding of physical phenomena occurring within the system (e.g. low collector flow-rate effects). Direct application of this model makes it possible to establish partial sizing rules for the system components: storage capacity, storage insulation, pipe insulation, heat-exchanger area, collector flow-rate

Anorexigen-induced pulmonary hypertension and the serotonin (5-HT) hypothesis: lessons for the future in pathogenesis

Epidemiological studies have established that fenfluramine, D-fenfluramine, and aminorex, but not other appetite suppressants, increase the risk of primary pulmonary hypertension (PH). One current hypothesis suggests that fenfluramine-like medications may act through interactions with the serotonin (5-hydroxytryptamine [5-HT]) transporter (5-HTT) located on pulmonary artery smooth muscle cells and responsible for the mitogenic action of 5-HT. Anorexigens may contribute to PH by boosting 5-HT levels in the bloodstream, directly stimulating smooth muscle cell growth, or altering 5-HTT expression. We suggest that individuals with a high basal level of 5-HTT expression related to the presence of the long 5-HTT gene promoter variant may be particularly susceptible to one or more of these potential mechanisms of appetite-suppressant-related PH

Simulation of Control Options for HVAC Management of a Typical Office Building

Disponible à l'adresse : http://www.harmonac.info/index.php?id=300International audienceAn investigation of correction of defects, as Energy Conservation Opportunities (ECOs) in HarmonAC project, can be done to fulfill two objectives: to improve thermal comfort and to reduce energy consumption of buildings. Among defect correction, HVAC control appears as a way of significant improvement. HVAC control is examined by using a dynamic simulation to improve the management of HVAC system for two opportunities: centrally, one opportunity is to sequence better Winter and Summer mode; locally, another one is the modification of internal set points to adapt to external climatic conditions. Adaptive comfort is examined to develop new rules for local control. Energy impact and thermal comfort of these two ECOs is investigated in the paper. An analysis of thermal comfort criterion shows that applying the operative temperature of EN15251 increases the consumption of the simulated building compared with a simple temperature control. According to our definition of heating and cooling modes, a good management of water network pumps for a four pipes system can reduce their consumption by 33%. A method to determine heating and cooling seasons is proposed to provide sufficient thermal comfort. A proposal to model the reasoned use of air conditioning equipment are investigated, it achieves a good thermal comfort and reduces the cooling load by 7% for Liege location

Procedures to identify Energy Conservation Opportunities applied to HVAC system: example of VSD of chilled water pumps

International audienceA procedure to identify energy savings of variable speed drive (VSD) applied to chilled water network is proposed. The purpose is to identify on which type of building and climate this opportunity can be preferably examined among the list of Energy Conservation Opportunities (137) identified in the HARMONAC project [1]. First, a preliminary analysis of the likely energy savings is led using two methodologies. A simplified approach is proposed in order to create parametric benchmarks. Results of the parametric simulations for several representative buildings of the French stock can be used to select this ECO according to the approximate potential of energy savings. The effect of appliance loads and climatic condition are examined. These procedures, to identify ECOs on site, could be used to be integrated into inspection procedures across Europe in order to apply Article 9 of Energy Performance of Buildings Directive (EPBD)

Graphical language for identification of control strategies allowing Demand Response

Proceedings are available at http://iet.jrc.ec.europa.eu/energyefficiency/conference/6th-international-conference-energy-efficiency-domestic-appliances-and-lighting-eedal11Presentation is available at http://www.eedal.dk/Conference/~/media/EEDAL/Sessions/Session%201/Graphical_language_for_identification_of_control_strategies_allowing_Demand_Response_Silva_Duplessis_Adn.ashxInternational audienceDue to new innovations in communication systems, electrical appliances are now capable of participating actively in smart grids control management. Each appliance has already several controls incorporated. In order to determine the best way to control an appliance in a smart grid context, we present a methodology based on a graphical language, which makes possible an easy identification of the available control strategies and will be used for future developments in terms of smart controls. The Language is divided into two different levels of complexity with different results. First level: Based on an empirical description of the controls available to the user, a first graphical representation of the appliance operation can be produced. This will allow the identification of the electric appliance availability for demand response control strategies based on the appliance existing controllers. Second level: This level requires detailed information and/or measurements of the appliance operation, so that more complex control strategies can be deduced. Due to the more complex operation description some of the deduced strategies, for this second level, could need adding new controls to allow their correct application. However it is up to the user of the language to choose the degree of the description complexity. This second level allows the user to know which components are the more energy and power demanding and how they are controlled, meaning that more accurate strategies can deducted. Manufacturers and power utilities can then identify their control strategies to be implemented in terms of demand response for electrical appliances

Evaluation as a "Learning-by-Doing" Tool for the Implementation of Local Energy Efficiency Activities

International audienceWith the "think global, act local" trends, local levels are taking an increasing role in the implementation of action plans, especially in the field of energy efficiency. An inventory of local energy efficiency operations in France confirmed a significant expansion of these activities, but also highlighted how rare their evaluation is, although a rich methodological evaluation material is available. The research question for this study was then how to fill the gap between theory and practice. This was addressed through studying the issue of evaluation use. The first step was to find in the evaluation literature the key components of evaluation use and the success factors to overcome the barriers to evaluation practice previously identified. This was used to adjust our evaluation methods and approach, and then to apply this to a particular case study. Key success factors for evaluation use were highlighted, such as the constructive and regular contacts between evaluators and program partners, and presenting the evaluation as a win-win collaboration. Finally, the main evaluation use was not to quantify the results of the operation, even if it was initially the most important stakeholder expectation, but to learn how to work together, how to supervise and use an evaluation, and how to improve the operation management and the operations themselves. This way, the evaluation really appears to be a learning-by-doing tool for all stakeholders involved in the implementation of local energy efficiency activities

Autonomie budgétaire et financière des universités et nouveau système d\u27allocation des moyens (SYMPA) : le chemin de la vertu ?

Rapport d\u27information n° 532 (2008-2009) de MM. Philippe ADNOT et Jean-Léonce DUPONT, fait au nom de la commission de la culture et de la commission des finances. Une synthèse du rapport est disponible en ligne : http://www.senat.fr/rap/r08-532/r08-532-syn.pd

Evaluation as a "Learning-by-Doing" Tool for the Implementation of Local Energy Efficiency Activities

International audienceWith the "think global, act local" trends, local levels are taking an increasing role in the implementation of action plans, especially in the field of energy efficiency. An inventory of local energy efficiency operations in France confirmed a significant expansion of these activities, but also highlighted how rare their evaluation is, although a rich methodological evaluation material is available. The research question for this study was then how to fill the gap between theory and practice. This was addressed through studying the issue of evaluation use. The first step was to find in the evaluation literature the key components of evaluation use and the success factors to overcome the barriers to evaluation practice previously identified. This was used to adjust our evaluation methods and approach, and then to apply this to a particular case study. Key success factors for evaluation use were highlighted, such as the constructive and regular contacts between evaluators and program partners, and presenting the evaluation as a win-win collaboration. Finally, the main evaluation use was not to quantify the results of the operation, even if it was initially the most important stakeholder expectation, but to learn how to work together, how to supervise and use an evaluation, and how to improve the operation management and the operations themselves. This way, the evaluation really appears to be a learning-by-doing tool for all stakeholders involved in the implementation of local energy efficiency activities

A functional analysis of electrical load curve modelling for some households specific electricity end-uses

Proceedings are available at http://iet.jrc.ec.europa.eu/energyefficiency/conference/6th-international-conference-energy-efficiency-domestic-appliances-and-lighting-eedal11Presentation is available at http://www.eedal.dk/Conference/~/media/EEDAL/Sessions/Session%207/EEDAL_GRANDJEAN_Arnaud_Presentation.ashxInternational audienceIn the next decades the European residential sector will face a series of deep technical and behavioural breaks. Among them are : the integration of new electrical domestic end-uses, the development of plug-in hybrid and electric vehicles, the increase of heat pumps implementations, the improvement and the technological changes in small electrical appliances. This will imply some behavioural modifications in the lifestyles. For example, the wishes in terms of comfort and the way electrical devices are used will evolve significantly. The energy consumption is likely to increase but the residential load curve will also be strongly modified. We then propose a functional analysis which enables to take into account, for each end-use, according to its own specificities, the key points that allow to build-up a relevant load curve. This will lead us to step down at the appliance level which will be the starting point of our modelling method. After a general description of the methodology, we will present three case studies for the following end-uses: washing, cooling and lighting. We will consider for each device the main determining factors of which are the technical features, the occupancy patterns of the household members, the activity scenarios in the dwellings, the climate. This bottomup approach will generate intrinsically some kind of diversity needed to represent the temporality and the level of the power demand for a large number of households. This methodology allows, after an aggregation step, the calculation of the load curves for households at various spatial scales